1. Field of the Invention
The present invention relates, in general, to refrigerators and, more particularly, to a cooling air supplying structure for a refrigerator having cantilever shelves, which is capable of supplying cooling air to all the divisions of its refrigerator compartment at the same time without the loss of the usability of the shelves, thereby reducing the temperature difference in its refrigerator compartment without side effects.
2. Description of the Prior Art
FIGS. 1a and 1b are sectional views showing the general construction of a conventional refrigerator having cantilever shelves and, particularly, the cooling air circulating structure of the refrigerator.
As illustrated in the drawings, the interior of the refrigerator is divided into a freezer compartment 10 and a refrigerator compartment 30 by means of a barrier 20 that is filled with adiabatic material. An evaporator 12, through which a coolant of low temperature and low pressure passes, is mounted to the interior of a heat exchange chamber 11 that is situated in the rear portion of the freezer compartment 10. A fan 14 is provided over the evaporator 12 so as to forcibly send cooling air, which is generated in the evaporator 12, to the freezer compartment 10 and the refrigerator compartment 30.
A cooling air supplying passage 22, through which cooling air generated in the evaporator 12 of the heat exchange chamber 11 is supplied to the refrigerator compartment 30, and an air returning passage 24, through which air warmed while being circulated in the refrigerator compartment 30 is returned toward the evaporator 12, are formed in the barrier 20.
Referring to the drawings, the interior structure of the refrigerator compartment 30 is described in the following.
As shown in the drawings, the lower end of the cooling air supplying passage 22 formed in the barrier 20 is connected to a cooling air discharging unit 32. The cooling air discharging unit 32 is widely formed in the ceiling of the refrigerating compartment 30 and serves to discharge the cooling air supplied to the refrigerating compartment 30 to the lower portion of the interior of the refrigerating compartment 30. Additionally, a vegetable compartment 36 is provided in the lower portion of the refrigerator compartment 30, and a machine room M, in which a compressor, etc. are mounted, is formed in the lower, rear portion of the refrigerator.
The above-described construction is different from the construction of a general refrigerator without having cantilever shelves. In the construction of the general refrigerator without cantilever shelves, a cooling air supplying duct is vertically formed behind the refrigerator compartment 30 and on the cooling air supplying duct, a plurality of cooling air discharging holes are respectively formed on the divisions of the refrigerator compartment, thereby supplying cooling air to each of the divisions.
It is due to the mounting structure of cantilever shelves that the construction of the refrigerator having cantilever shelves is different from the construction of a general refrigerator.
Referring to FIG. 1b, the mounting structure of cantilever shelves is described in detail.
Generally, each of cantilever shelves 34 comprises a shelf body (not shown) on which food, drink, etc. are positioned and a support bracket (not shown) that is used to mount the shelf body to the interior of the refrigerator compartment 30. As illustrated in FIG. 1b, a plurality of shelf channels 38a each having a plurality of engagement holes 38axe2x80x2 are vertically mounted on the inner case 38 of the refrigerator compartment 30. The shelf channels 38a serve to retain the cantilever shelves 34 with the hooks of the support brackets respectively inserted into and engaged with the engagement holes 38axe2x80x2 of the shelf channels 38a. 
In order to retain cantilever shelves 34 securely, two side shelves and one central shelf channel 38a are respectively and vertically mounted to both side portions and the central portion of the inner case 38 of the refrigerator chamber 30. In such a case, the mounting position of the central shelf channel 38a conflicts with the mounting position of the cooling air supplying duct of the general refrigerator without the cantilever shelves. Therefore, it is difficult that the refrigerator compartment 30 of the refrigerator having cantilever shelves is provided with the cooling air supplying duct.
Hereinafter, the circulation of the cooling air in the refrigerator having cantilever shelves is described with reference to FIGS. 1a and 1b. 
Of the cooling air that is generated in the evaporator 12 mounted in the heat exchange chamber 11 of the refrigerator, a portion and the remaining portion of the cooling air are respectively supplied to the freezer compartment 10 and the refrigerator compartment 30 by means of the fan 14.
The cooling air that is supplied to the refrigerator compartment 30 descends down to the cooling air discharge unit 32 formed in the ceiling of the refrigerator compartment 30 through the cooling air supplying passage 22 formed in the barrier 20. The cooling air discharged from the cooling air discharge unit 32 enters the interior of the refrigerator compartment 30, and, subsequently, is supplied to divisions partitioned by the cantilever shelves 34 and the vegetable compartment 36 over a certain period of time.
The cooling air supplied to the refrigerator compartment 30 through the process is warmed in the process of the heat exchange with items stored in the refrigerator compartment 30, and the warmed air is returned toward the evaporator 12 through the air returning passage 24 formed in the barrier 20.
The coolant exchanges heat with the air in the evaporator 12 of the freezer compartment 10. The evaporated gaseous coolant enters the compressor 40 mounted in the machine room M. The coolant that has entered the compressor 40 is compressed and, thereafter, sent to a condenser (not shown). The condensed liquid coolant of low temperature and high pressure is depressurized in a capillary tube (not shown) and, thereafter, supplied to the evaporator 12 of the freezer compartment 10. This cycle is repeated continuously.
However, the conventional refrigerator having cantilever shelves has the following defects.
As illustrated in FIG. 1b, the cooling air supplied to the refrigerator compartment 30 is discharged via the cooling air discharging unit 32 formed in the ceiling of the refrigerator compartment 30, and, subsequently, is supplied from an uppermost cantilever shelf to a lowermost cantilever shelf over a certain period of time. As a result, the air of relatively high temperature reaches the lower shelves, which decreases its cooling speed. This hinders the interior of the refrigerator compartment 30 from being cooled uniformly. Additionally, since it is difficult for a consumer to confirm whether the cooling air reaches the lowermost shelf only by eyesight, the consumer cannot be convinced of the cooling performance of the refrigerator.
The reason for this is that the cooling air supplying duct cannot be mounted to the center portion of the inner case 38 of the refrigerator chamber 30 because the central shelf channel 38a is vertically mounted to the central portion of the inner case 38 of the refrigerator chamber 30.
On the other hand, when the cooling air supplying duct is mounted to the inner case 38 of the refrigerator compartment 30 while the cantilever shelves 34 are supported by means of the two side shelf channels 38a without the central cantilever channel 38a, the weight of the items that can be put on the cantilever shelves 34 is limited because the support force for the retaining of the cantilever shelves 34 is decreased.
Incidentally, when the cooling air supplying duct and the central shelf channel 38a are mounted to the inner case 38 of the refrigerator compartment 30, the central shelf channel 38a should be mounted over the cooling air supplying duct. In such a case, since the central shelf channel 38a is projected away from the cooling air supplying duct, a recess should be formed on the cantilever shelf 38a so as to receive the central shelf channel 38a, or the size of the cantilever shelf 38a should be decreased. Therefore, the appearance of the shelves is deteriorated and the space of storage on the shelves is reduced.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a cooling air supplying structure for a refrigerator having cantilever shelves, which is capable of reducing the temperature difference in the interior of the refrigerator while preventing its appearance from being deteriorated and its size from being reduced.
In order to accomplish the above object, the present invention provides a cooling air supplying structure for a refrigerator having shelves, comprising a cooling air supplying duct for supplying cooling air to the upper and lower portions of the refrigerator compartment of the refrigerator, the cooling air supplying duct being vertically mounted behind the refrigerator compartment, a plurality of shelf channels each having a plurality of engagement slits, at least one of the shelf channels being mounted to the cooling air supplying duct, and a plurality of shelves respectively secured to the shelf channels.
The cooling air supplying duct may be vertically recessed on its central portion, and the channel mounted to the cooling air supplying duct may be positioned within the recessed portion of the cooling air supplying duct.
A plurality of cooling air discharging holes may be formed along the side portions of the cooling air discharging duct beside the recessed portion of the cooling air supplying duct.